'91 Cavalier RS won't start

[robk46]

Ive got a '91 Cavalier RS with the 3.1 v6. It started and ran fine today, my wife goes to move it and it just dies. I was putting new speakers in it, and I briefly removed the radio, then put it back in. Here's what I've done so far to troubleshoot.

Checked fuel pressure - 43 PSI
It's making a yellowish spark to the plugs I checked (#2 and #4)
Replaced the crank sensor


When I try to start it, it will crank over normally. If I let it sit for a while, it will almost catch, then just crank like it's not getting any fuel or spark. Could a bad coil pack just fail while it's running and shut the car down? What about when I removed the radio? Could there be some soft of factory anti-theft system in it?

[rhandwor]

You have a module under the pack of 3 coils. The Haynes Manual has pictures on how to check this. Ask Auto Zone or Advanced Auto I think they will check it free if you take it in. Yor should also have a crankshaft position sensor. If you attempt to remove it soak it with penetrating oil first. Use an ohm meter analog type with the sensor unplugged put one wire on each lead terminal it should sweep the meter as you crank the engine.

[robk46]

Update: I replaced the Crankshaft position sensor, but it didn't help. I'm not getting any voltage to the injectors, and I can't hear my injectors fire if I put my mechanics stethoscope to one of them. What could cause this? I see there's an ignition control module. Is there a relay or fusable link in the circuit somewhere?

[rhandwor]

If you used a noid light and you didn't have power. Use a logic probe and check if your getting power to the injector. Then check if your getting ground to the injector.
http://www.autopart.com/tools/toolsmain/tool/T_3401.htm
http://www.autopart.com/tools/toolsmain/tool/T_3031.htm
The links are pictures of the tools. I'm not sure on this but on older Ford's the power comes from the fuel pump relay. The computer pulses the ground based on signals from the camshaft position sensor and camshaft position sensor.
A DVOM or 12 volt test light will check for power. But the ground has to be verified. Look for blown fuses,bad harness,bad computer. I would personally ohm the wires from the computer to the injector.
http://www.alldata.com/ has good wiring diagrams appx. $26.95 for a years service. I personally wouldn't attempt without a wiring diagram.
Use starting fluid to verify it will run first just don't spray on airflow sensor.